It is known that satellite-based positioning systems comprise a constellation of navigation satellites placed in medium altitude orbits (of the order of 25 000 km) around the Earth. These navigation satellites and their orbits are generally designated in the art by “MEO satellites” and “MEO orbits”, respectively (Medium Earth Orbit). The navigation satellites are distributed uniformly in several orbital planes, in such a way that, at any point of the Earth, a user can see several navigation satellites, that is to say be in direct lines with them (at least three, but four if the user wishes to know his altitude) and deduce therefrom his own terrestrial coordinates. Moreover, at least one terrestrial monitoring center, cooperating with communications stations distributed over the surface of the Earth, is provided to ensure the nominal operation of the constellation of navigation satellites.
To improve the management of said constellation of navigation satellites, it has already been proposed that said monitoring center and said terrestrial communication stations be supplemented with management satellites placed in high orbits (of the order of 45 000 km), able to at least partially manage said navigation satellites and to communicate with the Earth.
It goes without saying that the manufacture, deployment, use and operation of such management satellites in high orbits represent considerable costs, so that it is advantageous to limit the number of said management satellites.